Answer:
37 minutes
Explanation:
We start by finding the difference between the original amount and what is left
Mathematically, that will be;
20-13.34 = 6.66
To
cents that will be 6.66 * 100 = 666 cents
We now divide by the amount per minute
The amount per minute is 18 cents
Thus, the number of minutes will
be 666/18 = 37
